Black Tank Vent

[Mike Groves]

All,

Fred's post on another topic prompted me to post this.

Recently at Pacific Shores, while intending just to partially fill my black tank using the sani-flush, my attention was broken and I forgot all about the fact that I had the water running into the tank with valve closed.  While my goal was 30% full, well, having forgotten all about it (I had gone off to help Margaret get some laundry), my panicked step daughter met me at the door saying the water's running over.  Not really putting 2 and 2 together I just though oh, another problem, I'd better turn off the water supply.  As I was turning it off, I remember my faux pas.

Unlike Fred's experience, which had the water coming out the vent on the roof (lucky for him), evidently either the only vent on my roof is connected to the grey water, or the easiest path of escape was up through the toilet (I think there is an overflow in it). 

Maybe my question is for other '99 Marquis owners like Tom, but is my one vent designed to cover both tanks, or do I not really have a vent on the toilet?  Even though my manual says the sink faucet also runs to the toilet, I've tested that, and that's not true, so the only entry to my black water is through the toilet.

Thanks,
Mike

[David T. Richelderfer]

If your coach toilet is built like a residential toilet, then brown water can come up through its gooseneck into the bowl, and when high enough it would simply overflow onto the loo's floor.  I know a lady who went into her home's loo and discovered a large rat in the bowl trying to make its escape.  Fortunately the bowl and rat were wet making it slippery enough that the rat was unable to gain enough traction to escape.  It soon made its way back down through the toilet to (I guess) try another home's toilet.

Both of my coaches have toilets with "plates" that move to cover the under side of the drop hole when not flushed and move away from covering the drop hole when flushed.  I doubt the "plates" seal tightly enough to prevent brown water under pressure from coming up into the bowl, but I suspect the "plates" are tight enough to make most brown water go up the vent pipe... especially with a water hose attached and turned relatively full flow.  Then there is the floor seal.  Many of them are not tight fitting either.  But that's another story...

[Fred Brooks]

             Hi Mike,

        Back in the late nineties, the common engineering thought was that waste tanks needed more water in them than normal usage would provide. Someone came up with the notion lets plumb the Lavy sink drain into the waste tank. Well they did that for a while but customers complained so they stopped. I can't give you dates because I don't remember.
         As far as venting is concerned, most manufacturers try to install a dedicated vent for the grey tank and another for the waste. RVIA states if there is no room to do that they will allow you to "Y" them together into a common vent so long as it is 1 1/2" diameter and 5 feet above the floor.
           If your waste tank was not vented at all, and you had water in the toilet bowl, when you went to flush it, it would burp because no room for the water to displace the air.
           Sorry to start this discussion, Regards Fred

[Michael Rump]

When we dumped our black tank recently, we tried to use the santi-flush, but was fairly sure it was not working.  After researching, we discovered that if it wasn't used regularly the nozzle (s) could plug up. As this is probably the case, is there any way to clean the nozzles to get them working again?

Appreciate your help!

[Mike Groves]

I think I might attach my air hose to the sani-flush if it was blocked and blow pressure through it.  That might work.

Mike

[Fred Brooks]

           Hi 2 Mikes,

      The sani-flush is plumbed from the water inlet to a vacuum breaker above the floor line inside the coach and then to the waste tank flusher. It has about 6-8 sprayer holes on the end. If you travel with your waste tank more than 1/3 full, the "wave action" will force toilet paper and waste into these sprayer holes. The usual fix is to locate the sprayer (usually on the passenger side end of the tank) remove and clean out with a pick tool and hot soapy water then compressed air, then reinstall with tacky tape taking caution not to strip out the mounting holes in the plastic tank. Confirm the repair by running water to the flusher and check for leaks.
           Hope this helps, Fred

[Tom and Pam Brown]

Mike, my Marquis has 2 vents side by side.  One for each tank.  I assume it's possible the previous owner could have installed a Y pipe.  Inside of your closet across from the toilet there is an encased area on the left, that's where the vents go up.  It's has screws to provide access.  I think it may be worth a look.

[Mike Groves]

Thanks Tom!  I will take a look.  I know that on the roof there is a single stack so it must be a Y.  Nice to have a fellow '99er around even though I know you were/are trying to sell it.

Mike

[Tom and Pam Brown]

No problem Mike, yea, we need a bit bigger Coach, we just added the third granddaughter and we are short on sleeping quarters.  Otherwise, I,would just keep the beast!

[Greg Kamper]

Tom and Pam,
I don't mean to hi-jack the post... but we had the same problem with room, although our 3 are our our kids... we built a dinette and converted our table to be used with the new dinette and I found a 3 tiered gas strut table lift to convert out dinette into a bed. The corian table top is a bit heavy so we just pull the leaf out when lifting it up then lock it in place and place the leaf back in. We keep the folding chairs in the closet so we can seat 5 at the table. This is the gas pedestal we used, although ours is black.
 http://shop4seats.com/rv-furniture/dinettes/dinette-hardware/springfield-gas-powered-table-pedestal.html
We found ours at walmart, but it's the same one.

[Joel Ashley]

Our solution to 3 "kids"  , 4 grandkids  , and now 4 great grandkids  is called a tent, pitched just off the patio  .  They like it better out there anyway.

-Joel and Lee